What is the definition of a simple sentence?

A simple sentence is defined as a sentence that expresses a complete thought with a subject and a verb. This structure is fundamental to English syntax, consisting of a single independent clause that conveys a clear idea. For instance, the sentence "The dog barks" is simple because it includes a subject ("the dog") and a verb ("barks"), and together they form a complete thought.

The other options do not accurately capture the essence of a simple sentence. A sentence containing two independent clauses aligns more with the definition of a compound sentence. A sentence that describes an unrelated idea does not adhere to the structural and functional requirements of a complete thought with cohesive subject-verb pairing. Lastly, a question typically falls under a different category, known as an interrogative sentence, which aims to elicit information rather than simply stating an idea. Thus, option B correctly illustrates what constitutes a simple sentence.